I was pretty much prepared to hate this, to dismiss it as a silly exercise on both fronts--on introducing a "story" to a chess game, and on implementing a chess endgame in a parser game.
But no. In fact it ended up working for me. The story was a little silly, perhaps, but the "you won't get her back" aspect of it did elevate it a little; and as a chess ending, you're right, it's pleasantly surprising. In the end it worked for me far, far more than I expected.